Electric cleaner

ABSTRACT

A separation wall ( 212 ) with a larger thickness than a separation wall ( 209 ) is provided at the central part in a left/right direction of a suction inlet main body ( 201 ). This is made so that the central part of a separate suction inlet passage ( 211 ) has a smaller height in a thickness direction than both sides in the left/right direction of the separate suction inlet passage. As a result, a separate suction inlet passage ( 211   b ), connected to a concentration opening ( 210 ) from the left and right sides at the front of the separate suction inlet passage ( 211 ), has a larger height than a separate suction inlet passage ( 211   a ) at the central part of the separate suction inlet passage ( 211 ). This way, plural suction inlets are provided in the suction inlet main body, and each of the suction inlets can be selectively used depending on each cleaning on floor surfaces.

TECHNICAL FIELD

The present invention relates to the structure of a suction inlet of an electric vacuum cleaner.

BACKGROUND ART

In an electric vacuum cleaner, dust is suctioned, together with airflow generated by the operation of an electric blower, through a suction inlet, and then the suctioned air flow is introduced into a dust collector to collect the dust. An example of a conventional electric vacuum cleaner of this type in which the suction inlet body is provided with a suction inlet is disclosed in Japanese Patent Application Published No. H8-164095.

The structure as described in the above-mentioned Japanese Patent Application Published NO. H8-164095 has a single suction inlet, and thus brings about a problem that suction characteristics cannot set individually in accordance with a plurality of floors, such as a carpet, wooden floor, and tatami.

DISCLOSURE OF THE INVENTION

In view of the above-mentioned problem, it is an object of the present invention to provide an electric vacuum cleaner having a suction inlet body provided with a plurality of suction inlets that can be selectively used depending on different cleaning operations on a plurality of floor surfaces.

To achieve the object described above, according to one aspect of the present invention, a suction inlet body is provided with a plurality of suction inlets, and, of suction inlet passages respectively connecting with the plurality of suction inlets, at least one is provided with adjusting means for adjusting air passage volume in a predetermined portion of the corresponding suction inlet. Moreover, a suction inlet switch device is provided which switches among the plurality of suction inlets for use.

Providing a plurality of suction inlets in this way permits setting suction characteristics in one suction inlet body in accordance with different usages. Providing the aforementioned passage with the means for adjusting the air passage volume in the predetermined portion of the suction inlet permits providing uniform wind speed at different portions of the suction inlet connecting with this passage, thus permitting steady suction, which results in improved suction performance. Moreover, if the air volume is adapted to increase at both side portions, even when the suction inlet cannot be provided in both the right and left ends of the suction inlet body, dust can be suctioned even in the regions at both the right and left sides of the suction inlet body, thus resulting in improved suction performance of the suction inlet body.

Specifically, the separate suction inlet passage running along the front and the top of the suction inlet passage is provided with adjusting means for adjusting the air passage volume in a predetermined portion of the separate suction inlet, thus permitting the air passage volume to be adjusted gradually with no difficulties even in a region having a long passage. This permits the adjustment of the air passage volume with little loss, thus achieving further improvement in the suction performance.

The adjusting means is so formed as to give the suction inlet passage provided therewith a different thickness-direction spatial dimension in a predetermined portion thereof. This permits the adjustment of the air passage volume in the suction inlet passage and the separate suction inlet passage where a relatively long air passage process can be set. In addition, since the air passage volume can be changed by changing the passage in the thickness direction, the air passages communicates with each other, thus forming one space without any obstacles. This permits the adjustment of the air passage volume with little loss, thus achieving even further improvement in the suction performance.

Portions of the suction inlet passage leading from the both side portions of the suction inlet inward has a thickness-direction spatial dimension greater than another portion of the suction inlet passage. This increases the air passage volume at the both sides of the suction inlet body, which permits adapting the width of the suction inlet to be smaller than the width of the suction inlet body while providing the remaining width portions of the suction inlet body as reinforcement portions, thus achieving the suction inlet body having great impact strength.

A partition wall between the separate suction inlet passage provided with the adjusting means and the suction inlet passage adjacent thereto has, on the side thereof facing the adjacent suction inlet passage, a partition wall surface that is rectilinear in the right/left direction. This permits setting the air passage condition of the suction inlet passage regardless of the change in the separate suction inlet passage, which permits freely setting the suction inlet and the separate suction inlet, thus easily achieving the suction inlet body provided with suction inlets well suited to their respective usages. In addition, the exterior on the separate suction inlet passage side of the suction inlet body can be formed by a smooth surface that has no convex and concave portions, thus achieving the suction inlet body with good appearance.

The thickness-direction dimension of the suction inlet passage as measured at the inward side is greater than or equal to a thickness-direction dimension of the suction inlet passage as measured at the suction inlet side. This permits achieving the suction inlet body with the aforementioned suction inlet passages that encounter little waste clogging.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a perspective view of the electric vacuum cleaner according to a first embodiment of the present invention.

FIG. 2 is a vertical cross section of the electric vacuum cleaner.

FIG. 3 is a partially horizontal cross section of the main body of the electric vacuum cleaner.

FIG. 4 is a side view of the electric vacuum cleaner, with its suction inlet body cross-sectioned.

FIG. 5 is a partially enlarged cross section of the suction inlet body in a different condition from the condition shown in FIG. 4.

FIG. 6 is a perspective view of the suction inlet switch device.

FIG. 7 is an exploded perspective view of the suction inlet switch device.

FIG. 8 is a perspective view of the inner structure of the suction inlet body.

FIG. 9 is a partial perspective view of the inner structure of the same suction inlet body as viewed from a different direction from the direction from which FIG. 8 is viewed.

FIG. 10 is a cross section of a suction inlet body, broken away at its front center, as viewed from the side.

FIG. 11 is a diagram of the suction inlet body as viewed from above.

FIG. 12 is a side view of the usage state of the electric vacuum cleaner with its suction inlet body cross-sectioned.

BEST MODE FOR CARRYING OUT THE INVENTION

The structure of an electric vacuum cleaner 1 according to a first embodiment of the present invention will be described with reference to FIGS. 1 to 12. In the following description, it is defined that the electric vacuum cleaner 1 is placed in the front, and the user operates the electric vacuum cleaner 1 while standing behind it. It is thus defined that the side where the user stands is the rear side of the electric vacuum cleaner 1 and the side opposite thereto is the forward side (front side) of the electric vacuum cleaner 1. In terms of the right and left, when the electric vacuum cleaner 1 is viewed from forward (the front), it is defined that the left side of the observer is the left side of the electric vacuum cleaner 1 and the side opposite thereto is the right side of the electric vacuum cleaner 1.

The electric vacuum cleaner 1 is an upright type and is divided into two major parts. One of the parts corresponds to a vacuum cleaner body 10, and the other part corresponds to a suction inlet body 70. A shell forming the suction inlet body 70 (e.g. shell formed of synthetic resin) has structure as described below. The suction inlet body 70 has a flat box-shaped central shell 71 on the center thereof and side shells 72 and 73 on the right and left sides thereof, respectively. The rear portions of the side shells 72 and 73 project more backward than the central shell 71, forming rear projections 74 and 75, respectively. The suction inlet body 70 has a C-shaped, planar form as a whole, and receives the vacuum cleaner body 10 between the rear projections 74 and 75.

The vacuum cleaner body 10 is formed of two shell portions. One of the shell portions is a cylindrical blower shell 11, and the other shell portion is a dust collector holder 12 that projects from the blower shell 11. The blower shell 11 has an electric blower 13 arranged therein (see FIG. 2). The axis of the electric blower 13 and the axis of the blower shell 11 are substantially parallel to each other and are both substantially horizontal.

The blower shell 11 is arranged between the rear projections 74 and 75 of the suction inlet body 70 with the axis thereof substantially horizontal, so that the spindle arranged on the axis thereof is fitted with the rear projections 74 and 75. In the rear projection 74 side, a spindle 14 projecting from the end surface of the blower shell 11 is rotatably supported by a bearing 76 provided in the rear projection 74. In the rear projection 75 side, a drive shaft 15, i.e., the extension of the motor shaft of the electric blower 13, enters into the rear projection 75. A cylindrical spindle (omitted from the figure) that wraps the drive shat 15 is projected from an end surface of the blower shell 11 so as to be rotatably supported by a bearing 77 provided in the rear projection 75. The blower shell 11 is coupled with the suction inlet body 70 by these spindles on the right and left sides so as to be rotatable around the horizontal axis.

The dust collector holder 12 is hollow-shaped, and formed long and slender as a whole, i.e., lies longitudinally. The longitudinal direction of the dust collector holder 12 is substantially perpendicular to the axis of the blower shell 11. The dust collector holder 12 projects not from the center of the blower shell 11 but one-sidedly from either the left or right thereof. In the first embodiment, the dust collector holder 12 projects from the left of the blower shell 11.

To one side of the dust collector holder 12, there are provided a base 16 and an overhang 17 for supporting the bottom and the top, respectively, of a dust collector to be described later. The base 16 is so provided as to stand upward from the blower shell 11. The overhang 17 is formed on the side surface of the dust collector holder 12. Both the base 16 and the overhang 17 are located in the space above the blower shell 11, i.e., right of the dust collector holder 12. Between the base 16 and the overhang 17, there is provided a rear support wall 18 which supports the left half of the dust collector to be described later from behind (see FIG. 3). The rear support wall 18 is formed on the side surface of the dust collector holder 12.

Numeral 20 represents a dust collector. In a cylindrical dust cup 21, the dust collector 20 swirls airflow at high speed so as to collect dust in a cyclone method. As shown in FIG. 2, the inside of the dust cup 21 is divided by a horizontal wall 22 into two sections: upper and lower chambers. The upper section is a centrifuge chamber 23, and the lower section is an exhaust chamber 24.

On the side surface of the centrifuge chamber 23, there is provided an air inlet 25 which is arranged at such location and angle as to generate airflow swirling along the inner peripheral wall of the centrifuge chamber 23.

In the center of the centrifuge chamber 23, there is arranged an exhaust pipe 26 which is a cylindrical basket-like member having an open upper portion and a closed lower portion. The exhaust pipe 26 has the upper open portion bonded to a vent 27, which is formed on the center of the horizontal wall 22, so as to be supported by the horizontal wall 22 in a drooping manner. A filter 28 of fine meshes woven with synthetic fiber, such as nylon, is attached to the outer peripheral surface of the exhaust pipe 26.

To the lower end of the exhaust pipe 26, there is fitted a stabilizer 29 which has four fins radially combined together so as to have a cruciate horizontal cross-section, with the end thereof reaching the vicinity of the bottom of the dust cup 21. The stabilizer 29 promotes the separation of dust from airflow and also reduces the movement of dust accumulated on the bottom of the dust cup 21.

The dust collector 20 is provided with an access opening by an appropriate technique for the purpose of discarding dust in the dust cup 21 and cleaning the filter 28. For example, the access opening may be achieved by providing structure such that an opening is provided in the top of the dust cup 21 and then covered with a lid so that, when the lid is opened, the exhaust pipe 26 and the stabilizer 29 can be pulled out together with the horizontal wall 22. Alternatively, the access opening may be achieved by providing the dust collector 20 with the dust cup having upper-and-lower-section structure including the exhaust chamber 24 and the centrifuge chamber 23 that are removable from the body of the dust collector.

An air outlet 30 is formed in the exhaust chamber 24. As shown in FIG. 3, both the air inlet 25 and the air outlet 30 are provided in the side surface of the dust collector 20 which faces the dust collector holder 12. The air inlet 25 and the air outlet 30 are oriented in the same direction, i.e., substantially leftward.

For the air inlet 25 of the dust collector 20, a first air passage 31 is provided. For the air outlet 30, a second air passage 32 is provided. The first air passage 31 communicates with a suction inlet (to be described in detail later) of the suction inlet body 70, and directs airflow suctioned through the suction inlet to the air inlet 25. The second air passage 32 communicates with a suction inlet of the electric blower 13, and directs airflow discharged through the air outlet 30 to the electric blower 13.

The first air passage 31 is mainly formed of a flexible hose 33. One end of the flexible hose 33 is fixed to one end of a connecting pipe 34 (see FIG. 3) provided horizontally in the dust collector holder 12. The other end of the connecting pipe 34 serves as an outlet 35 of the first air passage 31, to which an air inlet 25 of the dust collector 20 is connected. A seal ring 36 is fitted to the outlet 35 in order to maintain air tightness when connected with the air inlet 25. The other end of the flexible hose 33 is removably fitted with a connecting pipe 78 that projects from the top surface of the side shell 72 of the suction inlet body 70. The connecting pipe 78 communicates with the suction inlet.

The first air passage 31 may be mainly formed of a tubular body instead of a flexible hose. For example, the flexible hose may be replaced with a plurality of hard pipes elastically connected together. The tubular body may be of any type which can absorb the difference in the distance from the connecting pipe 34 to the connecting pipe 78 between when the vacuum cleaner body 10 is upright and when it is tilted, and also which does not become crushed when the inner pressure declines below the atmosphere pressure.

The second air passage 32 is formed of the hollow portion itself of the dust collector holder 12. The upper area of the hollow portion is partitioned off by a wall 12 a (see FIG. 2), so that the second air passage 32 does not communicate with the overhang 17. In the side surface of the dust collector holder 12, an inlet 37 of the second air passage 32 is formed at a position corresponding to the air inlet 30 of the dust collector 20. A seal ring 38 is fitted to the inlet 37 in order to maintain air tightness when connected with the outlet 30.

As shown in FIG. 2, the bottom end of the second air passage 32 reaches the bottom of the blower shell 11. An outlet 39 is provided in the side wall of the bottom end of the second air passage 32, to which a suction inlet 13 a of the electric blower 13 is directly connected through a vibration-proof cushion 40 that also serves for maintain air tightness.

The dust collector 20 is fitted to the dust collector holder 12 by being pressed against the dust collector holder 12 in a manner such that the longitudinal direction of the dust collector 20 agrees with the longitudinal direction of the dust collector holder 12. More specifically, the dust collector 20 is fitted by being inserted in the space surrounded by the base 16, the overhang 17, and the rear support wall 18.

On the upper end of the dust collector 20, there is provided a slide latch 43 which is constantly pressed upward by a spring, not shown, and comes into engagement with the edge of the overhang 17 at the final stage of the insertion of the dust collector 20. In this state, the dust collector 20 cannot be removed from the dust collector holder 12 unless the latch 43 is % pressed down against the spring, not shown, so as to be separated from the overhang 17.

The inside of the base 16 communicates with an exhaust space 50 into which the electric blower 13 exhausts air. Moreover, a filter 51 is inserted in the base 16. As the filter 51 collects fine dust that has passed through the filter 28 of the dust collector 20, a filter, such as HEPA (high-efficiency particulate air) filter, for example, may be used which offers higher filtering performance than the filter 28 does.

The airflow after the dust is trapped by the filter 51 returns into the chamber through an exhaust outlet 54 formed in the front surface of the base 16. The exhaust outlet 54 is formed of a plurality of horizontal slits aligned vertically.

Inside the overhang 17, there is arranged a controller 60 (see FIG. 2) which is connected to the electric blower 13 through a lead wire. The controller 60 controls the entire operation of the electric vacuum cleaner 1. The upper front portion of the overhang 17 serves as an operation panel 61 where various switch buttons are arranged. The operation panel 61 is easily operated since it is provided in the overhang 17.

A handle 62 separately molded is fixed with the tip of the dust collector holder 12. From the lower rear portion of the blower shell 11, there projects obliquely downward a bracket 63, to which wheels 64 (see FIG. 4) are fitted. There is provided one wheel 64 on each of the right and left ends of the blower shell 11. In front of the wheels 64, there are provided supporting legs 65, one on each of the right and left. Thus, when the dust collector holder 12 is placed perpendicularly, the vacuum cleaner body 10 is supported on the floor at four points thereof by the wheels 64 and the supporting legs 65.

Next, the structure of the suction inlet body 70 will be described below. As described above, the suction inlet body 70 is formed by providing on the left and right sides of the flat box-shaped central shell 71 the side shells 72 and 73, respectively, whose rear portions form the rear projections 74 and 75, respectively. The central shell 71 and side shells 72 and 73 are integrally molded together by, for example, synthetic resin.

The bottoms of the central shell 71 and the side shells 72 and 73 are open, and the openings are closed by a bottom plate 80. The bottom plate 80 has a plurality of suction inlets formed at the front portion thereof. The bottom plate 80 has a rear portion with a surface so inclined as to become higher increasingly rearward.

In the front portion of the bottom plate 80 of the first embodiment, two suction inlets are arranged one behind another. The first suction inlet 81 is elongated in the right-and-left direction, and has a width substantially equal to the width of the suction inlet body 70 excluding a belt-driving portion to be described later. The second suction inlet 82 is formed, located in the front side of and also in parallel to the first suction inlet 81. The second suction inlet 82 has the area of opening much smaller than that of the first suction inlet 81.

There are provided suction passages individually for the first and second suction inlets 81 and 82. The suction passage 83 for the first suction inlet 81 is formed in the bottom face of the central shell 71 (see FIG. 4). The suction passage 83 has a funnel-like form and has an air outlet 84 that is biased leftward, as viewed from the front.

The suction passage 85 for the second suction inlet 82 is arranged in such a manner as to overlap the suction passage 83. The suction passage 85 is formed between the top of the central shell 71 and a cover 86 removably fitted thereto with a space in between. The cover 86 has a front end thereof hooked over the central shell 71 and the rear end coupled with the central shell 71 by a screw or a latch 86 a so as to be kept fitted. The cover 86 is formed of transparent or semi-transparent material and permits viewing the inside of the suction passage 85 from outside. An air outlet 87 of the suction passage 85 is provided around the rear center of the suction passage 85.

Inside the rear projection 74 of the side shell 72, there is arranged a suction inlet switch device 90 which has in front of a valve casing 91 thereof air inlets 92 and 93 arranged vertically in series. The lower air inlet 92 is connected to the air outlet 84 of the suction passage 83. As shown in FIG. 4, the direct connection of the air outlet 84 to the air inlet 92 permits simple structure of the air passage and thereby improves flow efficiency. The upper air inlet 93 is connected to the air outlet 87 of the suction passage 85 via a hose, not shown.

In the top surface of the valve casing 91, there is provided an air outlet that is common to the air inlets 92 and 93. In the first embodiment, this air outlet itself is a connecting pipe 78 that is a start point of the first air passage 31.

There is arranged in the valve casing 91 a switch valve 95 which rotates within the vertical plane. The switch valve 95 is fitted to a valve axis 96 and rotates with the rotation of the valve axis 96. This rotation causes the switch valve 95 to selectively close one of the air inlets 92 and 93 while opening the other one. The structure of the suction inlet switch device 90 will be described later in detail. To both surfaces of the switch valve 95, there is fitted a seal member (not shown) formed of soft rubber or the like so as to provide better air tightness when the air inlets 92 and 93 are closed.

On the bottom surface of the suction inlet body 70, there are provided a first and a second ground support portions. The first ground support portion 101 is formed of wheels so provided as to be located near the second suction inlet 82, i.e., at the both ends of the second suction inlet 82 in this case.

The second ground support portion 102 is formed of a pair of right and left projections formed on the bottom plate 80. The second ground support portion 102 is provided behind the first suction inlet 81, around where the rear portion of the bottom plate 80 starts to incline. When the dust collector holder 12 is positioned upright, as shown in FIG. 4, the second ground support portion 102 supports the suction inlet body 70, and the first ground support portion 101 is lifted off the floor.

From the front end of the suction inlet body 70, there is projected a guide 103 which is located in front of the suction inlet 82 and has a width substantially equal to the total width of the suction inlet body 70. The bottom surface of the guide 103 becomes an inclined surface 104 (see FIG. 5) that increasingly lowers toward the second suction inlet 82. The front end of the inclined surface 104 is located about 3 mm higher than the entrance of the second suction inlet 82.

In the first suction inlet 81, there is provided an agitator 110. As the agitator 110, it is a common practice to use one formed by planting a plurality of rows of bristles in the circumference of a cylindrical rotating body at a predetermined angle. An agitator 110 may be used which is provided with a flake formed of rubber or soft synthetic resin instead of the rows of bristles. The axial direction of the agitator 110 is equal to the lateral width direction of the first suction inlet 81. The agitator 110 has part of the outer periphery thereof rotatably supported inside the suction inlet body 70 so as to project outward through the first suction inlet 81.

The source of rotational power of the agitator 110 is a drive shat 15 of the electric blower 13, from which the power is transmitted to the agitator 110 via the following power transmitting mechanism. As shown in FIG. 2, the drive shaft 15 is fixed with a power pulley 111. A belt 113 is wound around the power pulley 111 and a drive pulley (to be described later) that is so fixed with the shaft of the agitator 110 as to rotate integrally with the agitator 110. The power pulley 111 and the belt 113 are located inside the side shell 73. Alternatively, the belt 113 may be directly wound around the drive shaft 15 without fixing the separately provided power pulley 111 with the drive shaft 15.

There is aligned with the drive pulley an idler that is rotatable independently from the agitator so as to permit stopping the rotation of the agitator 110 during the operation of the electric blower 13. When the belt is placed over the idler, the idler only makes idle running, so that no power is transmitted to the agitator 110. Inside the side shell 73, there is provided a belt replacement device 120 for performing replacement of the belt 113. The structure of the belt replacement device 120 will be described later in detail.

The detailed structure of the suction inlet switch device 90 will be described with reference to FIGS. 6 and 7. The valve casing 91 of the suction inlet switch device 90 has an opening in the left side surface thereof. This opening is closed by a cover 131 which is fixed with the valve casing 91 by screws. In order to maintain good air tightness, a seal member 91 a is attached to the edge of the opening of the valve casing 91.

On the valve shaft 96, there are integrally formed a switch valve 95 and a lever 132. The valve shaft 96, the switch valve 95, and the lever 132 may be integrally formed by injection molding or the like by use of synthetic resin or metal. Alternatively, they may be separately formed, and then assembled and fixed together.

The valve shaft 96 has on the right end thereof a reduced diameter portion 96 a that projects to the right side surface of the valve casing 91 through a shaft hole (not shown) provided in the valve casing 91. The left portion of the reduced diameter portion 96 a is rotatably supported in such a manner as to be sandwiched between a concave portion 91 b that is formed in the inner surface of the valve casing 91 and has a semicircle cross section and a semicircle notch 131 a that is formed in the cover 131. That is, one bearing portion is formed by combining the concave portion 91 b and the notch 131 a together. The concave portion 91 b is located between the air inlets 92 and 93, and in the upstream side of airflow in the valve casing 91. Such arrangement of the concave portion 91 b in the upstream side of airflow is made for the purpose of preventing the operation of the switch valve 95 from being affected by dust caught around the valve shaft 96.

On the position of the shaft valve 96 exiting from the notch 131 a, there is integrally formed a lever 132 which is one component of an interlock means for interlocking the suction inlet switch device 90 with the belt replacement device 120. Because, in addition to the switch valve 95, the lever 132 is integrally formed, material provided with a predetermined level of strength, such as engineering-plastic-grade synthetic resin or metal, is used for the valve shaft 96.

The lever 132 has long and short arms 132 a and 132 b that project in mutually opposite directions. In the end of the long arm 132 a, there is provided a slit 132 c whose longitudinal direction agrees with the longitudinal direction of the log arm 132 a. A toggle spring 133 is arranged between the short arm 132 b and the cover 131.

The toggle spring 133 is formed of a torsion coil spring, with one end thereof engaged with the end of the short arm 132 b and with the other end thereof engaged with a hollow boss 131 b formed on the outer surface of the cover 131. The angular position of the valve shaft 96 where the short arm 132 b and the hollow boss 131 b approach closest to each other is a change point as a border that provides the switch valve 95 with power for closing the air inlet 92 or power for closing the air inlet 93.

To the left end of the valve shaft 96, there is fitted a pedal 134 for making switch operation with the switch valve 95 (see FIG. 1). The pedal 134 is arranged on a concave portion 74 a formed on the left upper corner of the rear projection 74 of the suction inlet body 70. The pedal 134 has front and rear portions forming together a certain angle relative to the center lying at the area where the valve shaft 96 is fitted, and thus looks bent when viewed from the side. Stepping on either the front or rear portion of the pedal 134, whichever is lifted, causes the pedal 134 to make seesaw-like movement, thereby rotating the valve shaft 96.

Next, the detailed structure of the belt replacement device 120 will be described with reference to FIGS. 8 and 9. The belt replacement device 120 is assembled mainly by a long, slender frame 141. The frame 141 is fixed inside the side shell 73 so that the longitudinal direction of the frame 141 is directed in the front-and-back direction of the suction inlet body 70. The belt 113 passes through the lower portion of the frame 141, and is replaced between the drive pulley 112 and the idler 114. The drive pulley 112 is fixed with the shaft 110 a of the agitator 110 so as to rotate integrally with agitator 110. The idler 114 is located on the right side of the drive pulley 112, and is rotatable independently from the agitator 110.

The frame 141 supports a spindle 142 that extends in the front-and-back direction. The axis line of the spindle 142 is parallel to the extension direction of the belt 113. The spindle 142 rotatably supports a fork 150 for moving the belt 113. The fork 150 is formed by a main body 151 made of metal and a rotatably supporting portion 152 made of synthetic resin that are so combined together as to be mutually non-rotatable. The main body 151 and the rotatably supporting portion 152 of the fork 150 are fixed together by insert molding, screwing, swaging, or the like. As the rotatably supporting portion 152 is made of synthetic resin, little noise is generated when it rotates with respect to the spindle 142.

The main body 151 of the fork 150 extends in front of the rotatably supporting portion 152 such that the longitudinal direction of the main body 151 is parallel to the extension directions of the spindle 142 and the belt 113. The main body 151 holds the belt 113 between a pair of parallel walls 151 a formed on the end thereof. The parallel walls 151 a extend in parallel to the main body 151 while being kept parallel to each other. The parallel walls 111 a are spaced at a predetermined distance from the rotatably supporting portion 152.

On the top of the rotatably supporting portion 152, there is provided an operation portion 152 a that projects in the form of knob. The operation portion 152 a projects outward through a window 75 a formed in the rear projection 75 of the suction inlet body 70. The area where the operation portion 152 a hits the vicinity of one end of the window 75 a is one rotation limit of the rotatably supporting portion 152. The area where the operation portion 152 a hits the vicinity of the other end of the window 75 a is the other rotation limit of the rotatably supporting portion 152. Specifically, the operation portion 152 a and the window 75 a form a stopper means 153 that defines the rotation limits of the fork 150. For hitting the window 75 a, the operation portion 152 a may hit the side shell 73 or the frame 141.

Between the rotatably supporting portion 152 and the frame 141, there is arranged a toggle spring, not shown, which is formed of a torsion coil spring, as is the case with the toggle spring 133. One end of the toggle spring engages with the rotatably supporting portion 152, and the other end thereof engages with the frame 141, thereby permitting smooth angle change of the rotatably supporting portion 152.

From the left side surface of the rotatably supporting portion 152, a lever 154 projects radially. On the left side surface of the frame 141, there is a lever 155 so supported as to be rotatable by a spindle 156 within the vertical plane. A slit 155 a provided in one arm of the lever 155 engages with the lever 154. The other arm of the lever 155 also has a slit 155 b. The longitudinal directions of the slits 155 a and 155 b agree with the direction in which the lever 155 itself extends.

The suction inlet switch device 90 and the belt replacement device 120 are coupled together by an interlocking means 160. The main part of the interlocking means 160 is a crank 161 formed by bending a steel rod or steel pipe into a substantially C shape. The crank 161 is rotatably supported inside the suction inlet body 70 so as to be rotatable about the horizontal axis by a pair of right and left bearings 162. The crank 161 has one end 161 a thereof engaged with the slit 132 c of the lever 132 on the suction inlet switch device 90 side. The crank 161 has the other end 161 b thereof engaged with the slit 155 b of the lever 155 on the belt replacement device 120 side. The lever 155, as well as the lever 132, is one component of the interlocking means 160.

The structure as described above, in which the C-shaped suction inlet body 70 sandwiches the vacuum cleaner body 10 with the suction inlet switch device 90 arranged in one end of the suction inlet body 70 and the belt replacement device 120 arranged in the other end thereof, permits certain portions of the suction inlet switch device 90 and the belt replacement device 120 to overlap the left and right sides of the vacuum cleaner body 10, thereby permitting reduction of the size, particularly the size in the front-and-right direction, of the suction inlet body 70.

Next, how the electric vacuum cleaner 1 operates will be described below. When the electrical vacuum cleaner 1 is not in operation, i.e. is in storage, as shown in FIG. 4, the dust collector holder 12 is in an upright state, and the vacuum cleaner body 10 is four-point-supported on the floor by two each of the wheels 64 and the supporting legs 65. For the suction inlet body 70, the second ground support portion 102 supports the suction inlet body 70, and the first ground support portion 101 is lifted off the floor. The agitator 110 is also not in contact with the floor.

In order to use the electric vacuum cleaner 1, a code, not shown, is extended and then connected to an outlet. With the handle 62 held in one hand, as shown in FIG. 12, the dust collector holder 12 is tilted to change its posture in preparation for cleaning. Then the vacuum cleaner body 10 acts like a lever. Specifically, the handle 62 serves as a power point of the lever, the wheel 64 serves as the fulcrum of the lever, and the spindle 14 and the drive shaft 15 (i.e., the cylindrical spindle surrounding the drive shaft 15) serve as working points of the lever. Thus, the spindle 14 and the drive shaft 15 (i.e., the cylindrical spindle surrounding the drive shaft 15) lift up the rear portion of the suction inlet body 70, and the supporting legs 65 separates from the floor.

When the vacuum cleaner body 10 is tilted to the point where the handle 62 reaches the height of between 60 cm and 80 cm from the floor, the second ground support portion 102 separates from the floor, and the front portion of the bottom plate 80 having the first and second suction inlets 81 and 82 becomes substantially parallel to the floor. Consequently, the first ground support portion 101 and the agitator 110 make contact with the floor (see FIG. 5). The height of between 60 and 80 cm corresponds to the height of the handle 62 that permits an adult of average physical size to push and pull the electric vacuum cleaner 1 for cleaning.

In this state, the degree of projection of the first ground support portion 101 is adjusted so that the height (H₁ in FIG. 5) from the floor to the entrance of the second suction inlet 82 becomes 0.8 to 2 mm. The second suction inlet 82 approaches the floor up to this distance (0.8 to 2 mm), where the first ground support portion 101 hits the floor, and thus does not approach the floor any further.

Now, a predetermined switch provided on the operation panel 61 is operated to drive the electric blower 13. The electric blower 13 exerts suction power on the suction inlet body 70 via the suction inlet 13 a, and then through the second air passage 32, the dust collector 20, and the first air passage 31.

When the suction inlet 81 is selected by the suction inlet switch device 90, airflow is suctioned through the first suction inlet 81. When the suction inlet 82 is selected by the suction inlet switch device 90, airflow is suctioned through the second suction inlet 82. When the first suction inlet 81 is selected, the belt replacement device 120 places the belt 113 on the drive pulley 112. Thus, the agitator 110 is driven by the driving of the electric blower 13.

The following description is based on the assumption that the first suction inlet 81 has been selected by the suction inlet switch device 90. The rotating agitator 110 lifts up dust from the floor or a footcloth spread over the floor. When the agitator 110 is rotated on the floor of soft material (e.g. carpet having shag 4 to 20 mm long), the first ground support portion 101 sinks into the soft floor material. Thus, the agitator 110 and the first suction inlet 81 approach the soft floor material so that the dust is scooped out and suctioned powerfully. Providing a limit to the width of the first ground support portion 101 as viewed from the front (e.g. adapting the total front width of the first ground support portion 101 to be not more than half the width of the first suction inlet 81, or adapting each width of the ground support portion 101 to be 10 to 20 mm) ensures the sinking of the first ground support portion 101 into the soft floor material.

As described above, on the carpet, the first ground support portion 101 sinks into the shag of the carpet, so that the front portion of the bottom plate 80 supports the suction inlet body 70, thus ensuring the operability on the carpet. Adapting the space between the outer circumference of the agitator 110 and the rear edge of the first suction inlet 81 (G₁ in FIG. 5) to be between 5 and 10 mm can achieve a balance between operability and suction performance.

A height (H₂ in FIG. 5) from the floor to the tip of the guide 103 is about 3 millimeter (may be between about 3 and 4.5 mm) greater than the height (H₁ in FIG. 5) from the floor to the entrance of the second suction inlet 82; therefore, the dust on the carpet is not eliminated even when the front portion of the bottom plate 80 is in contact with the carpet. If the dust is rice-grain sized, the guide 103 overrides the dust, and the dust is induced into the first suction inlet 81. In order to ensure overriding performance over the dust, the inclination angle of the inclined surface 104 may be not more than 40 to 50 degrees with respect to the horizontal plane.

The dust scooped out by the agitator 110 enters the suction inlet 92 of the suction inlet switch device 90 together with the airflow flowing from the first suction inlet 81, then passes through the connecting pipe 78 from the inside of the suction inlet switch device 90, and then enters the first air passage 31. The airflow that has passed through the first air passage 31 enters through the air inlet 25 of the dust collector 20 into the centrifuge separator 23.

The airflow that has entered through the air inlet 25 swirls around the exhausted pipe 26 at high speed. The dust in the airflow is separated from the airflow by centrifugal force and thus stays at the bottom of the dust cup 21. The swirling airflow from which the dust has been separated is suctioned into the exhaust pipe 26 and then reaches the exhaust chamber 24. The dust that has not been separated by centrifugation is filtered by the filter 28. The air flow that has reached the exhaust chamber 24 flows outside through the air outlet 30.

The airflow that swirls in the centrifuge separator 23 swirls not only around the exhaust pipe 26 but also around the stabilizer 29, during which the dust contained in the airflow is separated from the airflow and drops on the bottom of the dust cup 21 when the airflow hits the fin of the stabilizer 29. Further continuation of the dust suction develops a dust ball on the bottom of the dust cup 21. The stabilizer 29 suppresses the motion of this dust ball to prevent the dust from stirring up again.

The airflow exiting from the dust collector 20 enters the second air passage 32. The second air passage 32 connects with the suction inlet 13 a in substantially the same plane, which permits the airflow to go straight into the suction inlet 13 a without any blockage and disturbance. As the hollow portion itself of the dust collector holder 12 forms the second air passage 32, the air passage of a large area can be provided, so that the circulation efficiency of the airflow also improves in this regard.

The airflow suctioned into the electric blower 13 is discharged into the exhaust space 50 and then enters the base portion 16. The fine dust not filtered by the filter 28 is filtered by the filter 51, and then the airflow is discharged through the exhaust outlet 54.

The belt 113 runs while the electric blower 13 is driven. No protection can be provided against the contact of the running belt 113 with the fork 150. However, the belt 113 makes contact with the parallel walls 151 a of the main body 151 made of metal. Therefore, although the temperature of the main body 151 inevitably increases due to frictional heat, unlike the one made of synthetic resin, the main body 151 does not overheat and thus does not get damaged, and also is less susceptible to friction. Moreover, as the parallel walls 151 a are spaced at the predetermined distance from the rotatably supporting portion 152, heat is radiated at the main body 151 located between the parallel walls 151 a and the rotatably supporting portion 152, so that excessive frictional heat is not transmitted from the parallel walls 151 a to the rotatably supporting portion 152.

In cleaning a corner of the room, the pedal 134 is operated to switch the suction inlet switch device 90 to the second suction inlet 82. Specifically, the state in which the switch valve 95 has the air inlet 92 open and the air inlet 93 closed is changed to the state in which the switch valve 95 has the air inlet 93 open and the air inlet 92 closed. In this state, the valve shaft 96 rotates counterclockwise (in the direction of an arrow A) as viewed in FIG. 8. Consequently, the lever 132 lifts up the end portion 161 a of the crank 161, and the entire crank 161 rotates within the bearings 162 clockwise (in the direction of an arrow B). With this movement, the end portion 161 b of the crank 161 lifts up the front portion of the lever 155, whereas the rear portion of the lever 155 comes down, pressing down the lever 154. This causes the fork 150 to rotate about the axis line of the spindle 142. The direction of this rotation is counterclockwise (the direction of an arrow C) as viewed from the front.

The rotation of the fork 150 counterclockwise as viewed from the front causes the parallel walls 151 a to move from the right to the left while drawing an arc with the radius thereof equal to the distance from the center of the spindle 121. With this movement, the belt 113 on the drive pulley 112 is replaced around the idler 114. The fork 150 rotates around the axis line parallel to the extension direction of the belt 113, and does not have structure that amplifies vibration at the parallel walls 151 a located at the end thereof. Therefore, the movement of the belt 113 is always stable. Further, the limits of rotation of the fork 150 are defined by the stopper means 153, thus permitting the belt 113 to be positioned at a predetermined location.

The parallel walls 151 a keep themselves parallel to the extension direction of the belt 113 however many times the rotatably supporting portion 152 is rotated. Therefore, deformation (twist, entanglement) of the belt 113 is small. This means that little damage occurs to the parallel walls 151 a and the belt 113.

When the electric blower 13 is out of operation and the drive shaft 15 is out of rotation, the replacement is not complete. Once the electric blower 13 starts to be driven, the belt 113 completely transfers to the idler 114. The same applies to when the belt 113 is replaced from the idler 114 to the drive pulley 112.

Switching from the first suction inlet 81 to the second suction inlet 82 may be achieved by operating the operation portion 152 a. Specifically, the operation portion 152 a is located at the right end of the window 75 a while the first suction inlet 81 is in use. Moving the operation portion 152 a to the left end of the window 75 a causes the fork 150 to rotate counterclockwise as viewed from the front, so that the belt 113 is replaced from the drive pulley 112 to the idler 114. Simultaneously, the lever 154 comes down to press down the rear portion of the lever 155. The front portion of the lever 155 comes up to lift up the end portion 161 b of the crank 161. The entire crank 161 rotates within the bearings 162 in the direction opposite to the arrow B, causing the end portion 161 a of the crank 161 to lift up the longer arm of the lever 132. This rotates the valve shaft 96 in the direction opposite to the arrow A, causing the switch valve 95 to transfer to the position that opens the air inlet 93 and closes the air inlet 92.

In suctioning dust by using the second suction inlet 2, the first ground support 101 stably maintains the space between the entrance of the second suction inlet 82 and the floor made of hard material at a predetermined value (0.8 to 2 mm). This ensures a dust passage between the second suction inlet 82 and the floor. The second suction inlet 82 has a smaller opening area than the first suction inlet 81, and thus the suction power concentrates in the narrow area. Thus, the airflow suctioned at high speed is generated at the entrance of the second suction inlet 82, so that the suction power acts on the dust which is stronger than is provided by the suction method that involves the rotation of the agitator. Providing the space at 0.8 to 2 mm permits efficient suction of sandy and powdery dust.

When the second suction inlet 82 is in use, the suctioned airflow passes through under the transparent or semi-transparent cover 86. This permits direct visual check of the suction condition of the dust. When the second suction passage 85 is clogged with waste, the cover 86 can be detached so as to remove the waste that is a cause of the passage clogging.

Dust can be suctioned not only by use of the first and second suction inlets 81 or 82, but also by use of the flexible hose 33. The flexible hose 33 can be pulled out of the connecting pipe 78, and a suction tool, such as a space nozzle or a furniture brush, can be fitted to the end of the flexible hose 33 to clean a narrow area or an area located high.

After the cleaning is completed, the electric vacuum cleaner 1 is carried to the storage area for storing the electric vacuum cleaner 1 not in use, and then the vacuum cleaner body 10 is postured for storage. That is, the dust collector holder 12 is positioned upright. Consequently, the rear portion of the suction inlet body 70 comes down, the second ground support portion 102 hits the floor serving as a support for the suction inlet body 70, and the first ground support portion 101 is lifted off the floor. The outer periphery of the agitator 110 is also lifted off the floor. Thus, even if the electric blower 13 is still being driven at this point of time, the agitator 110 does not rub against the floor, and thus does not scratch the floor.

As long as the dust collector holder 12 is positioned upright, the outer periphery of the agitator 110 does not make contact with the floor. Therefore, even when the dust collector holder 12 is held at this position for a long period of time, the bristles implanted in the agitator 110 (or the flake formed of rubber or soft synthetic resin) does not become deformed.

Once a large amount of dust is accumulated in the dust collector 20, the latch 43 is detached, the dust collector 20 is pulled out, and then the dust inside is discarded. The filter 28 is cleaned if necessary. Subsequently, the dust collector 20 is set in the original position. The use of transparent or semi-transparent material for molding the dust cup 21 permits easy check of how much dust is accumulated.

The widths of the second suction inlet 82 and the suction passage 85 may be broadened to the maximums. Specifically, the second suction inlet 82 and the suction passage 85 (the entrance portion thereof) may be broadened to such extent that the suction inlet body 70 is left only with the wall thicknesses of its right and left side walls. Although this results in a small decrease in the strength of the suction inlet body 70, the width of the second suction inlet 82 involved in the suctioning broadens, leading to even further improvement in the suction power.

FIG. 10 is a cross section of a suction inlet body 201 according to another example of the embodiment, broken away at its front center, as viewed from the side. FIG. 11 is a diagram of the suction inlet body as viewed from above, with a cover 203 removed for easier understanding of separate suction inlets 202. As shown in these figures, in the both peripheral sides of the separate suction inlets 202 located in the front side of a suction inlet 204, there are provided rollers 205 as supports.

The rollers 205 are rotatably fitted to a rear cover 207 of the suction inlet body 201 by roller shafts 206 that rotatably support the rollers 205. Numeral 208 represents a rotary brush, numeral 209 represents a partition wall, and numeral 210 represents a collective opening located in the rear side of the following passage. The partition wall 209 separates a separate suction inlet passage 211 extending from the separate suction inlets 202 from a suction inlet passage 214 extending from the suction inlet 204. On the surface of the suction inlet body 201 from the front to the right and left sides, there is fitted a bumper 216 formed of, for example, soft synthetic resin. Inside the suction inlet body 202, there is arranged an equivalent, not shown, of the above-mentioned suction inlet switch device 90 used for switching between the suction inlets.

In the central portion in the right-and-left direction of the suction inlet body 201, there is provided a little thicker partition wall 212 in order to make the thickness-direction dimension of the separate suction inlet passage 211 smaller than is provided at the right and left sides thereof. As a result, the spatial dimension of a separate suction inlet passage 211 b leading from the front right and front left sides to the collective opening 210 is greater in the thickness direction than the spatial dimension of a separate suction inlet passage 211 a located at the central portion of the separate suction inlet passage 211.

Thus, the air passage rate becomes greater in the separate suction inlet passage 211 b than in the separate suction inlet passage 211 a. Therefore, even when the width of the separate suction inlet 202 is made smaller than that of the suction inlet body 201, the suction power increases at the front right and front left sides, which permits reliable suction performed with the entire width of the suction inlet body 201. Then the remaining width of the suction inlet body 201 can form reinforcement portions 213, thus providing the suction inlet body 201 having great impact strength while maintaining good suction performance.

The reinforcement portions 213 are respectively located in front of side shells 72 and 73 provided on the right and the left, respectively, of a flat-box type central shell 71. The rear portions of the side shells 72 and 73 project more backward than the central shell 71, forming rear projections 74 and 75. The suction inlet body 201 has a C-shaped planer shape as a whole, and receives the vacuum cleaner body 10 between the rear projections 74 and 75.

A partition wall surface 215 on the suction inlet passage 214 side is rectilinear in the right-and-left direction; therefore, the air passage condition of the suction inlet passage 214 can be set regardless of the thickness-direction change in the separate suction inlet passage 211. This permits the usages of the suction inlet 204 and the separate suction inlet 202 to be freely selected from among, for example, for floor, for carpet, etc., thus easily achieving the suction inlet body 201 having suction inlets well suited for their respective intended usages. In addition, the exterior on the separate suction inlet passage 211 side of the suction inlet body 201 can be formed by a smooth surface that has no convex and concave portions even with a single wall, thus providing the suction inlet body 201 with good appearance.

The thickness-direction dimension of the separate suction inlet passages 211 a and 211 b in the collective opening 210 side are adapted to be larger than or equal to the thickness-direction dimension thereof in the separate suction inlet 202 side. This reduces the possibility of waste clogging occurring in the separate suction inlet passage 211. Moreover, since the air passage volume is adjusted by changing the thickness-direction dimension of the passage, the passages communicates with each other, thus forming one space without any obstacles. This permits the adjustment of the air passage volume with little loss, thus achieving even further improvement in the suction performance.

If the portion where the spatial thickness-direction dimension of the passage changes is so formed to have a surface that is increasingly inclined, instead of perpendicular or the like, adjustment loss is further reduced and also airflow is provided with little swirling, thus achieving the low-noise vacuum cleaner. If the minimum thickness-direction spatial dimensions of the separate suction inlet 202 and the separate suction inlet passage 211 are set at, for example, 6 mm or more, paper pieces cut by a shredder is less likely to become jammed.

As described above, the separate suction inlet passage 211, i.e., the passage running along the front and the top of the suction inlet passage 214, is provided with the adjusting means (the partition wall 212 in this embodiment) for adjusting the air passage volume in a predetermined portion of the separate suction inlet 202, the air passage volume can be adjusted gradually with no difficulties even in a region having a long passage. This permits the adjustment of the air passage volume with little loss, thus achieving further improvement in the suction performance. However, the provision of such an adjusting means is not limited to the separate suction inlet passage 211, but it can be further provided in the suction inlet passage 214 or in the both.

As described above, the air passage volume in the separate suction inlet passage 211 is adjusted from the partition wall 212 side. Alternatively, the adjustment of the air passage volume may be achieved by adjusting the thickness-direction spatial dimension of the passage from the cover 203 side. In this case, however, since the outer exterior of the cover 203 is formed without any concave and convex portions, if the wall of the cover 203 is formed by projecting only the separate suction inlet passage 211 side thereof, the weight of the cover 203 increases and it becomes difficult to make the cover 203 transparent to check how the dust is flowing in the passage, thus accompanied by deteriorated detachability and functionality. Further, the air passage volume can be adjusted by combination of the partition 212 side and the cover 203 side.

The above description refers to the method in which the adjusting means for adjusting the air passage volume gives the corresponding suction inlet passage a different thickness-direction spatial dimension in a predetermined portion. However, the adjusting means is not limited to this method. For example, a guide plate for adjusting the air passage volume may be provided in the relevant passage along the air passage route thereof, or an opening portion at a predetermined area, about 10 mm long, located in the central portion of the suction inlet may be sealed, though these measures result in small increase in air passage resistance. One of examples of the former is a guide plate provided in the separate suction inlet passage 211 such that the guide plate is located along part of the border between the separate suction inlet passage 211 a and the separate suction inlet passage 211 b shown in FIG. 11.

In the above-mentioned embodiment, the suction inlet 204 corresponds to the first suction inlet 81, and the separate suction inlet 202 corresponds to the second suction inlet 82. Moreover, the suction inlet passage 214 corresponds to the suction passage 83, the separate suction inlet passage 211 corresponds to the suction passage 85, the collective opening 210 corresponds to the air outlet 87, and the rotary brush 208 corresponds to the agitator 110.

From the above description, it is clear that various modifications of the present invention are permitted. Therefore, it would be appreciated that the present invention may be implemented by departing from the detailed description within the scope of the accompanying claims.

INDUSTRIAL APPLICABILITY

As described above, the present invention can provide an electric vacuum cleaner that has a suction inlet body provided with a plurality of suction inlets and that is capable of selectively using these suction inlets depending on a plurality of floors to be cleaned. 

1. An electric vacuum cleaner that suctions dust, together with airflow generated by operation of an electric blower, through a suction inlet of a suction inlet body and then introduces the auctioned airflow into a dust collector so as to collect the dust, wherein the suction inlet body is provided with a plurality of suction inlets and a plurality of suction inlet passages respectively connecting with the plurality of suction inlets, and wherein, at least one of the plurality of suction inlet passages is provided with adjusting means for adjusting a ratio of air passage volume in a center portion of the respectively connected suction inlet to air passage ratio in both side portions thereof, wherein the adjusting means is so formed as to change a thickness-direction spatial dimension of a portion of the at least one suction inlet passage leading from the center portion of the respectively connected suction inlet inward, and wherein thickness-direction spatial dimensions of portions of the at least one suction inlet passage leading from the both side portions of the respectively connected suction inlet inward is greater than the thickness direction spatial dimension of the portion of the at least one suction inlet passage leading from the center portion of the respectively connected suction inlet inward.
 2. The electric vacuum cleaner according to claim 1, wherein a suction inlet switch device is provided which switches among the plurality of suction inlets for use. 3.-6. (canceled)
 7. The electric vacuum cleaner according to claim 1, wherein a partition wall as a partition between the at least one suction inlet passage provided with the adjusting means and another of the plurality of suction inlet passages which is adjacent thereto and connecting with another respectively connected suction inlet has on a side thereof facing the another respectively connected suction inlet, a partition wall surface that is rectilinear in a right/left direction thereof.
 8. The electric vacuum cleaner according to claim 2, wherein a partition wall as a partition between the at least one suction inlet passage provided with the adjusting means and another of the plurality of suction inlet passages which is adjacent thereto and connecting with another respectively connected suction inlet has, on a side thereof facing the another respectively connected suction inlet, a partition wall surface that is rectilinear in a right/left direction thereof. 9.-11. (canceled)
 12. The electric vacuum cleaner according to claim 1 wherein, for each of the portions of the at least one suction inlet passage leading from the both side portions of the respectively connected suction inlet inward and the portion of the at least one suction inlet passage leading from the center portion of the respectively connected suction inlet inward, the thickness-direction spatial dimension as measured at an inward side is greater than or equal to the thickness-direction dimension passage as measured at a suction inlet side.
 13. The electric vacuum cleaner according to claim 2 wherein, for each of the portions of the at least one suction inlet passage leading from the both side portions of the respectively connected suction inlet inward and the portion of the at least one suction inlet passage leading from the center portion of the respectively connected suction inlet inward, the thickness-direction spatial dimension as measured at an inward side is greater than or equal to the thickness-direction dimension passage as measured at a suction inlet side.
 14. The electric vacuum cleaner according to claim 7 wherein, for each of the portions of the at least one suction inlet passage leading from the both side portions of the respectively connected suction inlet inward and the portion of the at least one suction inlet passage leading from the center portion of the respectively connected suction inlet inward, the thickness-direction spatial dimension as measured at an inward side is greater than or equal to the thickness-direction dimension passage as measured at a suction inlet side.
 15. The electric vacuum cleaner according to claim 8 wherein, for each of the portions of the at least one suction inlet passage leading from the both side portions of the respectively connected suction inlet inward and the portion of the at least one suction inlet passage leading from the center portion of the respectively connected suction inlet inward, the thickness-direction spatial dimension as measured at an inward side is greater than or equal to the thickness-direction dimension passage as measured at a suction inlet side. 